Não informado. (1893). Contributions from the Zoological Laboratory of the University of Pennsylvania. University of Pennsylvania, Zoological Laboratory.
Chicago-referens (17:e uppl.)Não informado. Contributions from the Zoological Laboratory of the University of Pennsylvania. Philadelphia, Pa: University of Pennsylvania, Zoological Laboratory, 1893.
MLA-referens (8:e uppl.)Não informado. Contributions from the Zoological Laboratory of the University of Pennsylvania. University of Pennsylvania, Zoological Laboratory, 1893.
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